中国力学学会史 = A history of Chinese society of theoretical and applied mechanics

《中国力学学会史》是《中国学会史丛书》之一。是一部全面系统记述中国力学学会建立与发展历程的专著。 《中国力学学会史》全书30万字，书中不但重点对学会的初创情况、发展过程、组织建设、学术交流、分支机构等进行了专门介绍，还特别收录了记述学会重大活动情况的大事记、名人与学会发展的丰富资料和一些极有史料价值的历史照片，旨在反映学会在不同时期的活动概况及其在中国力学界中发挥的桥梁与纽带作用。 中国力学学会是中国科协的组成部分，也是我国著名的学术团体之一，仅以此书的编著出版，纪念中国科协成立50周年和中国力学学会成立50多周年。本书可供力学界和科技界有关部门及工作者、各学会相关人员、大专院校师生参阅，也可作为组织和开展国内外学术交流研究的参考资料。

Enhancement and broadening of extreme-ultraviolet supercontinuum in a relative phase controlled two-color laser field

We experimentally demonstrate the generation of an extreme-ultraviolet (XUV) supercontinuum in argon with a two-color laser field consisting of an intense 7 fs pulse at 800 nm and a relatively weak 37 fs pulse at 400 nm. By controlling the relative time delay between the two laser pulses, we observe enhanced high-order harmonic generation as well as spectral broadening of the supercontinuum. A method to produce isolated attosecond pulses with variable width and intensity is proposed. (C) 2008 Optical Society of America.

Controlling wave propagation through nonlinear engineered granular systems

We study the fundamental dynamic behavior of a special class of ordered granular systems in order to design new, structured materials with unique physical properties. The dynamic properties of granular systems are dictated by the nonlinear, Hertzian, potential in compression and zero tensile strength resulting from the discrete material structure. Engineering the underlying particle arrangement of granular systems allows for unique dynamic properties, not observed in natural, disordered granular media. While extensive studies on 1D granular crystals have suggested their usefulness for a variety of engineering applications, considerably less attention has been given to higher-dimensional systems. The extension of these studies in higher dimensions could enable the discovery of richer physical phenomena not possible in 1D, such as spatial redirection and anisotropic energy trapping. We present experiments, numerical simulation (based on a discrete particle model), and in some cases theoretical predictions for several engineered granular systems, studying the effects of particle arrangement on the highly nonlinear transient wave propagation to develop means for controlling the wave propagation pathways. The first component of this thesis studies the stress wave propagation resulting from a localized impulsive loading for three different 2D particle lattice structures: square, centered square, and hexagonal granular crystals. By varying the lattice structure, we observe a wide range of properties for the propagating stress waves: quasi-1D solitary wave propagation, fully 2D wave propagation with tunable wave front shapes, and 2D pulsed wave propagation. Additionally the effects of weak disorder, inevitably present in real granular systems, are investigated. The second half of this thesis studies the solitary wave propagation through 2D and 3D ordered networks of granular chains, reducing the effective density compared to granular crystals by selectively placing wave guiding chains to control the acoustic wave transmission. The rapid wave front amplitude decay exhibited by these granular networks makes them highly attractive for impact mitigation applications. The agreement between experiments, numerical simulations, and applicable theoretical predictions validates the wave guiding capabilities of these engineered granular crystals and networks and opens a wide range of possibilities for the realization of increasingly complex granular material design.

Carrier-envelope phase control of carrier-wave Rabi flopping in asymmetric semiparabolic quantum well

We investigate the carrier-wave Rabi flopping effects in an asymmetric semiparabolic semiconductor quantum well (QW) with few-cycle pulse. It is found that higher spectral components of few-cycle ultrashort pulses in the semiparabolic QW depend crucially on the carrier-envelope phase (CEP) of the few-cycle ultrashort pulses: continuum and distinct peaks can be achieved by controlling the CEP. Our results demonstrate that by adjusting the CEP of few-cycle ultrashort pulses, the intersubband dynamics in the asymmetric semiparabolic QW can be controlled in an ultrashort timescale with moderate laser intensity. (c) 2008 Optical Society of America.

Fabrication of microfluidic optical waveguides on glass chips with femtosecond laser pulses

We describe the fabrication of microfluidic channel structures on the surface of a borosilicate glass slide by femtosecond laser direct writing for optical waveguide application. Liquid with a variable refractive index is fed into the microchannel, serving as the core of the waveguide. We demonstrate that either a multimode or a single-mode waveguide can be achieved by controlling the refractive index of the liquid. (C) 2007 Optical Society of America

Soundings: the Newsletter of the Monterey Bay Chapter of the American Cetacean Society. 2009

(PDF contains 88 pages.)

Conflito de interesses na sociedade de economia mista: interesse público versus interesse privado

A presente tese tem por objetivo tratar do conflito de interesses na sociedade de economia mista. Referida sociedade tem na sua base constitutiva o conflito como elemento inerente. Por possuir capital público e privado, não é fácil solucionar facilmente os problemas que se apresentam no decorrer de sua existência frente à possibilidade de que o detentor do poder de controle pode decidir em prol do interesse público. E é visando limitar a má utilização do interesse público como resposta à tomada de decisões por parte do acionista controlador que se propõe uma mudança de paradigma. Para tanto, propõe-se analisar o papel do Estado empresário na atual conjuntura de limitação de intervenção do Estado na economia. Também é abordada a forma com que o poder Executivo vem intervindo no mercado, de forma a limitar a livre iniciativa e, por vezes, até mesmo eivada de certa inconstitucionalidade. No entanto, para evitar que haja afronta à Constituição no que diz respeito à exploração de atividade econômica por parte do Estado sem que sejam observados os limites constitucionais impostos, apresenta-se o meta-interesse como meio de solução. Sendo o meta-interesse o interesse da própria companhia, e considerando que o interesse público que fundamenta a autorização para a criação da sociedade de economia mista se extingue com a criação da referida companhia, tem-se que as normas que devem reger as sociedades de economia mista são as normas de direito privado. Com o meta-interesse o Estado passa a intervir na seara privada em igualdade de condições com as demais companhias, não podendo mais se valer de sua posição de acionista majoritário para tomar decisões que conflitem com o interesse da companhia e que privilegiem o interesse público secundário ou até mesmo o interesse político do Estado em detrimento do interesse social e dos acionistas minoritários. Dessa forma, o meta-interesse tem por finalidade colocar fim aos conflitos em relação à aplicação das normas jurídicas e as indefinições da própria natureza da sociedade de economia mista.

Aquatic ecology, economy and society: the place of aquatic ecology in the sustainability agenda

This article explores aspects of sustainability and the importance of sustainable development, including the place of the crucially important resource of fresh water and of freshwater ecosystems. It examines the treatment of natural resources by the economic system that underpins global business, outlines some progress towards more sustainable approaches to business, and recommends steps to re-establish science as the driver of wise policies that contribute to sustainable development.

Upper level and phase controlling group velocity in V-type system

With the external field coupling the two upper levels, we investigate the light pulse propagation properties with weak probe field in a V-type system. Due to the external upper level (UL) coupling field, the dispersion of the system has been influenced by the relative phase. It is shown that the UL field and the relative phase can be regarded as switches to manipulate light propagation between subluminal and superluminal. (c) 2007 Elsevier B.V. All rights reserved.

Controlling the group velocity in a five-level K-type atomic system

The properties of a five-level K-type system are investigated. With the controlling fields, the properties of the dispersion and absorption of the system are changed greatly. The system can produce anomalous dispersion regions with absorption and normal dispersion regions with absorption or transparency. Furthermore, the group velocity can be varied from subluminal to superluminal by varying the intensity of the controlling field and the probe detunings in principle. (C) 2008 Elsevier B.V. All rights reserved.

Soundings: the Newsletter of the Monterey Bay Chapter of the American Cetacean Society. 2010

(PDF contains 92 pages.)

'Fa Tsai', a Chinese edible Nostoc in market. [Translation from: Bulletin of the Japanese Society of Phycology 8 124-126, 1960. ]

The Nostoc 'Fa Tsai' is sometimes seen in Chinese cooking materials stores. It is investigated what 'Fa Tsai' consists of and where it originates.

Studies on the mouth size of fish larvae. Method and conclusions only [Translation from: Bulletin of the Japanese Society of Scientific Fisheries 36, 353-368, 1970]

This study was conducted to look into the relationship between mouth size and the total length of larval fish, and the growth in total length of larval fish in one or within a one-year period. Study material was gathered in the South China Sea, the Bay of Bangkok and the Vietnamese coast. This translation focuses on methods and conclusions of the original (longer) paper.

Three-dimensional coupled wave study for finite-sized anisotropic volume holographic gratings under ultrashort pulsed beam readout

The three-dimensional coupled wave theory is extended to systematically investigate the diffraction properties of finite-sized anisotropic volume holographic gratings (VHGs) under ultrashort pulsed beam (UPB) readout. The effects of the grating geometrical size and the polarizations of the recording and readout beams on the diffraction properties are presented, in particular under the influence of grating material dispersion. The wavelength selectivity of the finite-sized VHG is analyzed. The wavelength selectivity determines the intensity distributions of the transmitted and diffracted pulsed beams along the output face of the VHG. The distortion and widening of the diffracted pulsed beams are different for different points on the output face, as is numerically shown for a VHG recorded in a LiNbO3 crystal. The beam quality is analyzed, and the variations of the total diffraction efficiency are shown in relation to the geometrical size of the grating and the temporal width of the readout UPB. In addition, the diffraction properties of the finite-sized and one-dimensional VHG for pulsed and continuous-wave readout are compared. The study shows the potential application of VHGs in controlling spatial and temporal features of UPBs simultaneously. (C) 2007 Optical Society of America